This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A381864 #78 May 30 2025 23:15:38
%S A381864 15,33,35,44,45,51,63,65,66,69,70,75,76,77,80,85,87,88,90,91,92,95,99,
%T A381864 102,104,105,115,119,123,130,133,135,138,140,141,143,144,145,152,153,
%U A381864 154,159,160,161,170,172,174,175,176,177,180,184,185,187,188,189,190
%N A381864 Numbers k in A024619 such that p^(m+1) == r (mod k) where r is also in A024619 for all p | n.
%C A381864 This sequence intersects neither A381750 nor A382120.
%H A381864 Michael De Vlieger, <a href="/A381864/b381864.txt">Table of n, a(n) for n = 1..10000</a>
%e A381864 Table of a(n) for n = 1..12, showing prime decomposition (facs(a(n))), p_x^(m+1) mod n, where x = 1 denotes the smallest prime factor, x = 2, the second smallest prime factor, etc. Brackets appear around residues that are not prime powers.
%e A381864 p_x^(m+1) mod n
%e A381864 n a(n) facs(a(n)) p_1 p_2 p_3
%e A381864 -----------------------------------------
%e A381864 1 15 3 * 5 12 10
%e A381864 2 33 3 * 11 15 22
%e A381864 3 35 5 * 7 20 14
%e A381864 4 44 2^2 * 11 20 33
%e A381864 5 45 3^2 * 5 36 35
%e A381864 6 51 3 * 17 30 34
%e A381864 7 63 3^2 * 7 18 28
%e A381864 8 65 5 * 13 60 39
%e A381864 9 66 2 * 3 * 11 62 15 55
%e A381864 10 69 3 * 23 12 46
%e A381864 11 70 2 * 5 * 7 58 55 63
%e A381864 12 75 3 * 5^2 6 50
%t A381864 nn = 190, Reap[Do[If[! PrimePowerQ[n], If[NoneTrue[Map[PowerMod[#, 1 + Floor@ Log[#, n], n] &, FactorInteger[n][[All, 1]] ], PrimePowerQ], Sow[n]]], {n, 2, nn}] ][[-1, 1]]
%Y A381864 Cf. A000961, A024619, A381750, A382120.
%K A381864 nonn
%O A381864 1,1
%A A381864 _Michael De Vlieger_, Apr 06 2025